How to implement AES encryption?

package util;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import org.apache.tomcat.util.codec.binary.Base64;

/**
*
* @author Administrator
*
*/
public class AES {

// 加密
   public static String Encrypt(String sSrc, String sKey) throws Exception {
       if (sKey == null) {
           System.out.print("Key为空null");
           return null;
       }
       // 判断Key是否为16位
       if (sKey.length() != 16) {
           System.out.print("Key长度不是16位");
           return null;
       }
       byte[] raw = sKey.getBytes("utf-8");
       SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
       Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");//"算法/模式/补码方式"
       cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
       byte[] encrypted = cipher.doFinal(sSrc.getBytes("utf-8"));

return new Base64().encodeToString(encrypted);//此处使用BASE64做转码功能，同时能起到2次加密的作用。
   }

// Decryption
public static String Decrypt(String sSrc, String sKey) throws Exception {
                                                                                                                                                                                                                                                 
# System.out.print("Key is null");
16) {
            System.out.print("Key length is not 16 bits");
                                              return null; #Secretkeyspec Skeyspec = New Secretkeyspec (raw, "aes");
cipher cipher = cipher.getInstance ("AES/ECB/PKCS5Padding"); Her.DeCrypt_mode, Skeyspec);
byte[] encrypted1 = new Base64().decode(sSrc);//Use base64 to decrypt first
            try {
            byte[] original = cipher.doFinal(encrypted1); original,"utf-8");
                                                                                  return originalString; }
} Catch (Exception EX) {
System.out.println (ex.tostring ());
Return null;
}
}
/**
* Encryption
*
* @param content Content that needs to be encrypted
* @param password Encryption password
* @return
*/
public static byte[] encrypt(String content, String password) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128, new SecureRandom (password.getBytes()); retKeySpec key = new SecretKeySpec(enCodeFormat, "AES") ;
                                                                                                                                                                                                                                            to be cipher.init(Cipher.ENCRYPT_MODE , key);// Initialization
              byte[] result = cipher.doFinal(byteContent);                   e.printStackTrace();
        } catch (NoSuchPaddingException e) {                         e.printStackTrace();
            } catch (InvalidKeyException e) {      );
      } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();    
          } catch (IllegalBlockSizeException e) {  
                   e.printStackTrace();  
           } catch (BadPaddingException e) {  
                   e.printStackTrace();  
           }  
           return null;  
   }  
   /**Decryption
* @param content Content to be decrypted
* @param password Decryption key
* @return
*/  
   public static byte[] decrypt(byte[] content, String password) {  
           try {  
                    KeyGenerator kgen = KeyGenerator.getInstance("AES");  
                    kgen.init(128, new SecureRandom(password.getBytes()));  
                    SecretKey secretKey = kgen.generateKey();  
                    byte[] enCodeFormat = secretKey.getEncoded();  
                    SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");              
                    Cipher cipher = Cipher.getInstance("AES");// 创建密码器  
                   cipher.init(Cipher.DECRYPT_MODE, key);// 初始化  
                   byte[] result = cipher.doFinal(content);  
                   return result; // 加密  
           } catch (NoSuchAlgorithmException e) {  
                   e.printStackTrace();  
           } catch (NoSuchPaddingException e) {  
                   e.printStackTrace();  
           } catch (InvalidKeyException e) {  
                   e.printStackTrace();  
           } catch (IllegalBlockSizeException e) {  
                   e.printStackTrace();  
           } catch (BadPaddingException e) {  
                   e.printStackTrace();  
           }  
           return null;  
   }  
   /**Convert binary to hexadecimal
* @param buf
* @return
*/  
   public static String parseByte2HexStr(byte buf[]) {  
           StringBuffer sb = new StringBuffer();  
           for (int i = 0; i                    String hex = Integer.toHexString(buf[i] & 0xFF);  
                   if (hex.length() == 1) {  
                           hex = '0' + hex;  
                   }  
                   sb.append(hex.toUpperCase());  
           }  
           return sb.toString();  
   }  
   /**Convert hexadecimal to binary
* @param hexStr
* @return
*/  
   public static byte[] parseHexStr2Byte(String hexStr) {  
           if (hexStr.length()                    return null;  
           byte[] result = new byte[hexStr.length()/2];  
           for (int i = 0;iint high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16); ), 16);
                    result[i] = (byte) (high * 16 + low); [] args) throws Exception {
/*
* AES-128-ECB encryption mode is used here, and the key needs to be 16 bits.
*/
String cKey = "1234567890123456";
// String that needs to be encrypted
String cSrc = "www.gowhere.so";
System.out.println(cSrc) ;
// Encryption
String enString = AES.Encrypt(cSrc, cKey);
System.out.println("The encrypted string is: " + enString);

// Decrypt
String DeString = AES.Decrypt(enString, cKey);
System.out.println("The decrypted string is: " + DeString);
String content = "test";
String password = "12345678";

//Encryption

System.out.println("Before encryption: " + content);
byte[] encryptResult = encrypt(content, password);
String encryptResultStr = parseByte2HexStr(encryptResult);
System.out.println("After encryption: " + encryptResultStr);
//Decryption
byte[] decryptFrom = parseHexStr2Byte(encryptResul tStr);
byte[] decryptResult = decrypt(decryptFrom,password);
System.out.println("After decryption: " + new String(decryptResult));
}
}

The above is the detailed content of How to implement AES encryption?. For more information, please follow other related articles on the PHP Chinese website!